1. Field of the Invention
The present invention relates to a technique for characterization of a user using a network. More particularly, the present invention relates to an analysis system, an information processing apparatus, an activity analysis method and a program for analyzing the user using the characteristics of network nodes to propagate information.
2. Description of the Related Art
Recently, as computers and communication devices have improved their processing power, information communication has been performed through a network such as the Internet or WAN (Wide Area Network). The network is configured by including client computers (hereinafter simply called “client”) and a server computer (hereinafter simply called “server”). The clients and server configure network nodes.
A client is operated by a user identified by a user ID uniquely identifying the user. The user sends various requests to the server through the network and receives processing results from the server. Then, the user registers, in the server, information including various contents such as text, image, moving image data, audio data, and multimedia data, or takes actions including various processing such as search, buying a product, posting, chat, and update of a blog (Weblog) through an SNS (Social Network Service) provided by the server.
If the server provides an SNS function to the user, the user sends/receives information through actions such as to write a diary in a blog and read another person's blog through the client. Hereinafter, “information sending” means uploading of information to the server and “information receiving” means acquisition of information from the server.
In general, the activities of users to a network vary depending on the users' preferences, aims and access modes for the network. For example, a specific client uploads a diary to a blog system almost every day. Another client engages in an activity to post a comment for the information already registered, rather than uploading diaries. Still another client engages in an activity to search information exclusively in order to download information.
Systems for detecting information propagation through a network are known. For example, Japanese Patent Application No. 2006259801 (“Patent Document 1”) discloses an information utilization analysis/display device for managing information propagated through an “informal” network element, in which no client has been previously defined and therefore every client can participate, such as an organization allowing clients to voluntarily participate in a community, a bulletin board system, and a mailing list.
The information utilization analysis/display device disclosed in Patent Document 1 detects information propagated in a network element allowing a client to voluntarily participate in and the status of the information utilization propagated outside of the network element to display the utilization status of the information by means of configuration network elements, making an informal network element available as a business resource.
In Patent Document 1, an information utilization by a configuration element using information propagation through a network element is acquired to acquire information about users and the like included in an informal network configuration element. Thus, if the information propagation between users is analyzed, an information propagation route can be traced. However, it is not enough to generate only a directed graph using information propagation in order to analyze what role a user plays on the network using the information propagation on the network, that is, the activity of the user on the network.
Further, analysis of the activities of the user on the network reflects a difference from information that the user desire to acquire through the network. In this respect, Patent Document 1 enables acquisition of an information propagation route, but it does not detect for what purpose the client configures the information propagation route.
Japanese Patent Application No. 2007264718 (“Patent Document 2”) discloses a technique for estimating interest of a user in real time from words propagated between files circulated by the user. In Patent Document 2, the user acquires a plurality of words included in a file from the history of the file circulated by the user to determine an IDF value indicating the frequency of occurrence of the word propagated in the file in order to estimate the changing interest of the user in real time.
The changing interest of the user disclosed in Patent Document 2 is applied to the case when the user browses a specific content, and it does not characterize the activity of the user through the network.
Further, Japanese Patent Application No. 5233719 (“Patent Document 3”) discloses a technique for calculating relevance between pieces of information using a characteristic representing sentence and time data of information generation to associate between them. The technique disclosed in Patent Document 3 does not aim to characterize the activity of the user on the network. Thus, the propagation route and the activity of the user on the propagation route are detected to characterize the user. If the characterization is reflected in information distribution from an information processing device such as a server through the network, it can be expected that more efficient information distribution can be performed for the user accessing the network.
Thus, a technique which detects the purpose of a user connected to a network through a client propagates information, registers it, and reflects the activity of the user on the network in server's processing is desirable.
Further, a technique for detecting the activities of the user on the network is also needed to enable characterization of the user.